This invention relates to an axial pin tubular lock of the type in which a locking spindle is rotatably mounted in a tumbler sleeve and normally is held against rotation by pins extending axially between the tumbler sleeve and a driver ring. The tumbler sleeve is held in a rigidly fixed position in an outer barrel which serves to mount the lock in a cabinet door or the like.
The lock of the invention preferably is a resettable lock of the same general type as disclosed in Falk U.S. Pat. No. 3,961,507, although the principles of the invention are not limited to a resettable lock. In the present resettable lock, the driver ring is in the form of a sleeve which is keyed to rotate with the spindle and which is located adjacent a reset sleeve supported for selective rotation on the spindle. By using a reset key to rotate the reset sleeve relative to the driver sleeve, the code of the lock may be changed so as to require the use of a different service key to open the lock.
In certain prior tubular locks, it has been relatively easy to destroy the lock by hammering on the locking spindle with a punch from the front of the lock and knocking the spindle rearwardly. In some locks, rearward knock-out of the spindle is prevented only by virtue of a slightly enlarged shoulder on the forward end portion of the spindle engaging the forward face of the reset sleeve or driver sleeve around the inner periphery thereof. When the spindle is punched rearwardly, the shoulder shears away the inner peripheral portion of the reset sleeve and/or driver sleeve to free the spindle to first slide rearwardly and then to turn to an unlocked position.